Genetic Improvement of Seedling Emergence of Low‐Phytate Soybean Lines

Abstract

Reduced seedling emergence of low‐phytate (LP) soybean [Glycine max (L.) Merr.] lines with the pha1 and pha2 alleles has been a limiting factor in the development of LP cultivars. Crosses between normal‐phytate (NP) and LP soybean lines have produced progeny with improved emergence. The objective of this study was to determine if LP lines with improved emergence are capable of producing progeny with equal or higher emergence when crossed to NP parents. Low‐phytate lines with improved emergence were crossed to NP cultivars and the LP progeny were evaluated with seed produced at three 2007 locations and five 2008 locations. A field test of the lines was conducted in 2008 with one 2007 seed source. An extended cold test (ECT) was developed to evaluate all the lines with the three 2007 seed sources and selected lines and parents with the five 2008 sources. There were LP progeny with significantly less emergence than the LP parent when evaluated in the field and with the ECT. One single‐cross line had significantly greater emergence than the LP parent and emergence equal to the NP parent. Genetic variation among the single‐cross and backcross lines was attributed to the segregation of favorable and unfavorable alleles for emergence from both the NP and LP parents. Multiple seed sources should be used to identify LP lines with superior emergence based on field evaluations or the ECT.

Elevated Palmitate and Stearate Concentrations in the Oil of Low‐Phytate Soybean Lines

“…The three populations used in the study originated from crossing the LP line A08‐260001 to three LS lines developed by Iowa State University. A08‐260001 was chosen for its improved seedling emergence as described by Trimble and Fehr (2010). A08‐260001 was a F 3:6 line selected from the cross A05‐318011 × ‘IA2070’ that was homozygous for fap1 (C1726) and fap3 (A22).…”

“…The ground samples were dried for 48 h at 65°C and stored in a dessicator. Three replications of extractions were used to determine Pi according to a modification of the method of Chen et al (1956) as described by Trimble and Fehr (2010). The entries were randomized within each replication.…”

Legacy Nutrient Dynamics at the Watershed Scale: Principles, Modeling, and Implications

“…The episodic nature of surface runoff due to rainfall and thawing events induces carried nutrient experiencing transport-retention-remobilization alternant cycles before finally entering downstream waters, which prolongs sediment and nutrient travel time. The sediment and nutrient can accumulate rapidly (e.g., vertical accretion on floodplains) but which require much higher energy events or longer time frames to remove (e.g., through channel or bank erosion), referring to as "fast in-slow out" (Trimble and Fehr, 2010).…”

Phytase: An Enzyme to Improve Soybean Nutrition

“…However, consumption of soybean-derived products negatively affects non-heme Fe absorption (Derman et al, 1987) mainly due to the presence of phytic acid (Hurrell et al, 1992;Davidson et al, 2001;Hurrell, 2003), and to a lesser extent due to the glycinin fraction (11S) of soybean protein (Lynch et al 1994). Although several low-phytate barley or corn lines have been developed and tested for nutritional applications (Sugiura et al, 1999;Baxter et al, 2003;Applegate et al, 2003;Overturf et al, 2003), the low-phytate soybean line has shown a reduced seedling emergence (Meis et al, 2003;Oltmans et al, 2005;Trimble & Fehr, 2010). In contrast, Yuan et al (2009) have recently developed two new low phytic acid mutants and studied their nutritional properties.…”